1. The Field of the Invention
The invention relates to connectors for electrically connecting integrated circuit packages, known also as active device substrates (ADS), to printed circuit boards. The housings of the connectors in this particular area of the art are secured to the board permanently, relatively speaking. Accordingly, means are associated with the housings to removably retain the ADS therein.
2. The Prior Art
The active device substrates of interest herein are of the type having integrated circuit semiconductors, i.e., "chips", mounted on a ceramic substrate. Thin, conductive traces or pads radiate from the chip outwardly to the substrates four sides. The substrates are relatively fragile which presents a problem; i.e., means to bias the substrate against the contact elements with sufficient force to maintain good electrical contact without breakage. Clearly, the force must be applied uniformly to the substrate. Representative prior art patents meeting the aforementioned requirement include U.S. Pat. Nos. 4,130,327 and 4,220,383. Both patents disclose connectors having contact elements in an insulative housing into which an ADS is received. Contact surfaces on the upper ends of the elements engages the pads on the substrate. Leads or pins on the lower end of the elements in U.S. Pat. No. 4,130,327 are adapted for insertion into holes in a PCB. The lower ends of the elements in U.S. Pat. No. 4,220,383 are adapted for abutting engagement against traces on the board; i.e., a "surface to surface" connection. Both patents includes covers which bias the substrate against the aforementioned contact surfaces.
Further, both patents disclose contact elements which possess spring characteristics such that they can tolerate the downward deflection imposed on them by the cover without taking a set.